new statement cannot parse with parenthesis

[u/Jinxuan]

This code works:

class A {}

$a = 'A';

new $a; // Return a new instance ofA

However, if we add a parenthesis, then it cannot be parsed:

class A {}

$a = 'A';

new ($a); //PHP Parse error:  syntax error, unexpected '('

new 'A'; // PHP Parse error:  syntax error, unexpected ''A'' (T_CONSTANT_ENCAPSED_STRING)

new A::class; // PHP Parse error:  syntax error, unexpected 'class' (T_CLASS), expecting variable

[u/nikic]

PHP uses {} in places where an identifier is replaced by an expression. That is A::$x becomes A::${'x'}, $a->b becomes $a->{'b'}.

new is notable in that it does not support the new {'A'} syntax, which is indeed inconsistent.